CipherScan - Find out which SSL ciphersuites are supported by a target

Cipherscan tests the ordering of the SSL/TLS ciphers on a given target, for all major versions of SSL and TLS. It also extracts some certificates informations, TLS options, OCSP stapling and more. Cipherscan is a wrapper above the openssl s_client command line.

Cipherscan is meant to run on all flavors of unix. It ships with its own built of OpenSSL for Linux/64 and Darwin/64. On other platform, it will use the openssl version provided by the operating system (which may have limited ciphers support), or your own version provided in the -o command line flag.

Examples
Basic test:

$ ./cipherscan google.com
 ...................
 Target: google.com:443
 
 prio  ciphersuite                  protocols                    pfs                 curves
 1     ECDHE-RSA-CHACHA20-POLY1305  TLSv1.2                      ECDH,P-256,256bits  prime256v1
 2     ECDHE-RSA-AES128-GCM-SHA256  TLSv1.2                      ECDH,P-256,256bits  prime256v1
 3     ECDHE-RSA-AES128-SHA         TLSv1.1,TLSv1.2              ECDH,P-256,256bits  prime256v1
 4     ECDHE-RSA-RC4-SHA            SSLv3,TLSv1,TLSv1.1,TLSv1.2  ECDH,P-256,256bits  prime256v1
 5     AES128-GCM-SHA256            TLSv1.2                      None                None
 6     AES128-SHA256                TLSv1.2                      None                None
 7     AES128-SHA                   TLSv1.1,TLSv1.2              None                None
 8     RC4-SHA                      SSLv3,TLSv1,TLSv1.1,TLSv1.2  None                None
 9     RC4-MD5                      SSLv3,TLSv1,TLSv1.1,TLSv1.2  None                None
 10    ECDHE-RSA-AES256-GCM-SHA384  TLSv1.2                      ECDH,P-256,256bits  prime256v1
 11    ECDHE-RSA-AES256-SHA384      TLSv1.2                      ECDH,P-256,256bits  prime256v1
 12    ECDHE-RSA-AES256-SHA         SSLv3,TLSv1,TLSv1.1,TLSv1.2  ECDH,P-256,256bits  prime256v1
 13    AES256-GCM-SHA384            TLSv1.2                      None                None
 14    AES256-SHA256                TLSv1.2                      None                None
 15    AES256-SHA                   SSLv3,TLSv1,TLSv1.1,TLSv1.2  None                None
 16    ECDHE-RSA-AES128-SHA256      TLSv1.2                      ECDH,P-256,256bits  prime256v1
 17    ECDHE-RSA-DES-CBC3-SHA       SSLv3,TLSv1,TLSv1.1,TLSv1.2  ECDH,P-256,256bits  prime256v1
 18    DES-CBC3-SHA                 SSLv3,TLSv1,TLSv1.1,TLSv1.2  None                None
 
 Certificate: trusted, 2048 bit, sha1WithRSAEncryption signature
 TLS ticket lifetime hint: 100800
 OCSP stapling: not supported
 Cipher ordering: server

Testing STARTTLS:

darwin$ $ ./cipherscan --curves -starttls xmpp jabber.ccc.de:5222
 ................................
 Target: jabber.ccc.de:5222
 
 prio  ciphersuite                  protocols              pfs                 curves
 1     ECDHE-RSA-AES256-GCM-SHA384  TLSv1.2                ECDH,P-256,256bits  prime256v1
 2     ECDHE-RSA-AES256-SHA384      TLSv1.2                ECDH,P-256,256bits  prime256v1
 3     ECDHE-RSA-AES256-SHA         TLSv1,TLSv1.1,TLSv1.2  ECDH,P-256,256bits  prime256v1
 4     DHE-RSA-AES256-GCM-SHA384    TLSv1.2                DH,1024bits         None
 5     DHE-RSA-AES256-SHA256        TLSv1.2                DH,1024bits         None
 6     DHE-RSA-AES256-SHA           TLSv1,TLSv1.1,TLSv1.2  DH,1024bits         None
 7     DHE-RSA-CAMELLIA256-SHA      TLSv1,TLSv1.1,TLSv1.2  DH,1024bits         None
 8     AES256-GCM-SHA384            TLSv1.2                None                None
 9     AES256-SHA256                TLSv1.2                None                None
 10    AES256-SHA                   TLSv1,TLSv1.1,TLSv1.2  None                None
 11    CAMELLIA256-SHA              TLSv1,TLSv1.1,TLSv1.2  None                None
 12    ECDHE-RSA-AES128-GCM-SHA256  TLSv1.2                ECDH,P-256,256bits  prime256v1
 13    ECDHE-RSA-AES128-SHA256      TLSv1.2                ECDH,P-256,256bits  prime256v1
 14    ECDHE-RSA-AES128-SHA         TLSv1,TLSv1.1,TLSv1.2  ECDH,P-256,256bits  prime256v1
 15    DHE-RSA-AES128-GCM-SHA256    TLSv1.2                DH,1024bits         None
 16    DHE-RSA-AES128-SHA256        TLSv1.2                DH,1024bits         None
 17    DHE-RSA-AES128-SHA           TLSv1,TLSv1.1,TLSv1.2  DH,1024bits         None
 18    DHE-RSA-SEED-SHA             TLSv1,TLSv1.1,TLSv1.2  DH,1024bits         None
 19    DHE-RSA-CAMELLIA128-SHA      TLSv1,TLSv1.1,TLSv1.2  DH,1024bits         None
 20    AES128-GCM-SHA256            TLSv1.2                None                None
 21    AES128-SHA256                TLSv1.2                None                None
 22    AES128-SHA                   TLSv1,TLSv1.1,TLSv1.2  None                None
 23    SEED-SHA                     TLSv1,TLSv1.1,TLSv1.2  None                None
 24    CAMELLIA128-SHA              TLSv1,TLSv1.1,TLSv1.2  None                None
 
 Certificate: UNTRUSTED, 2048 bit, sha1WithRSAEncryption signature
 TLS ticket lifetime hint: None
 OCSP stapling: not supported
 Cipher ordering: client
 Curves ordering: server
 Curves fallback: False

Exporting to JSON with the -j command line option:

$ ./cipherscan --curves -j www.ebay.com | j
 {
     "curves_fallback": "False",
     "serverside": "True",
     "target": "www.ebay.com:443",
     "utctimestamp": "2015-04-03T14:54:31.0Z",
     "ciphersuite": [
         {
             "cipher": "AES256-SHA",
             "ocsp_stapling": "False",
             "pfs": "None",
             "protocols": [
                 "TLSv1",
                 "TLSv1.1",
                 "TLSv1.2"
             ],
             "pubkey": [
                 "2048"
             ],
             "sigalg": [
                 "sha1WithRSAEncryption"
             ],
             "ticket_hint": "None",
             "trusted": "True"
         },
         {
             "cipher": "ECDHE-RSA-DES-CBC3-SHA",
             "curves": [
                 "prime256v1",
                 "secp384r1",
                 "secp224r1",
                 "secp521r1"
             ],
             "curves_ordering": "server",
             "ocsp_stapling": "False",
             "pfs": "ECDH,P-256,256bits",
             "protocols": [
                 "TLSv1",
                 "TLSv1.1",
                 "TLSv1.2"
             ],
             "pubkey": [
                 "2048"
             ],
             "sigalg": [
                 "sha1WithRSAEncryption"
             ],
             "ticket_hint": "None",
             "trusted": "True"
         }
     ]
 }

Analyzing configurations
The motivation behind cipherscan is to help operators configure good TLS on their endpoints. To help this further, the script analyze.py compares the results of a cipherscan with the TLS guidelines from https://wiki.mozilla.org/Security/Server_Side_TLS and output a level and recommendations.

$ ./analyze.py -t jve.linuxwall.info
 jve.linuxwall.info:443 has intermediate tls
 
 Changes needed to match the old level:
 * consider enabling SSLv3
 * add cipher DES-CBC3-SHA
 * use a certificate with sha1WithRSAEncryption signature
 * consider enabling OCSP Stapling
 
 Changes needed to match the intermediate level:
 * consider enabling OCSP Stapling
 
 Changes needed to match the modern level:
 * remove cipher AES128-GCM-SHA256
 * remove cipher AES256-GCM-SHA384
 * remove cipher AES128-SHA256
 * remove cipher AES128-SHA
 * remove cipher AES256-SHA256
 * remove cipher AES256-SHA
 * disable TLSv1
 * consider enabling OCSP Stapling

In the output above, analyze.py indicates that the target jve.linuxwall.info matches the intermediate configuration level. If the administrator of this site wants to reach the modern level, the items that failed under the modern tests should be corrected.
analyze.py does not make any assumption on what a good level should be. Sites operators should now what level they want to match against, based on the compatibility level they want to support. Again, refer to https://wiki.mozilla.org/Security/Server_Side_TLS for more information.
Note on Nagios mode: analyse.py can be ran as a nagios check with --nagios. The exit code will then represent the state of the configuration:

2 (critical) for bad tls
1 (warning) if it doesn't match the desired level
0 (ok) if it matches. cipherscan can take more than 10 seconds to complete. To alleviate any timeout issues, you may want to run it outside of nagios, passing data through some temporary file.

OpenSSL
Cipherscan uses a custom release of openssl for linux 64 bits and darwin 64 bits. OpenSSL is build from a custom branch maintained by Peter Mosmans that includes a number of patches not merged upstream. It can be found here: https://github.com/PeterMosmans/openssl
You can build it yourself using following commands:

git clone https://github.com/PeterMosmans/openssl.git --depth 1 -b 1.0.2-chacha
 cd openssl
 ./Configure zlib no-shared experimental-jpake enable-md2 enable-rc5 \
 enable-rfc3779 enable-gost enable-static-engine linux-x86_64
 make depend
 make
 make report

The statically linked binary will be apps/openssl.

Contributors